In a previous post, “How the gun lobby has already blocked Boston’s bombing investigators,” I shared a video of Lawrence O’Donnell explaining how the NRA has already obstructed forensic officials from fully investigating the Boston Marathon explosions. MSNBC:

But a crucial piece of evidence called a taggant that could be used to trace the gunpowder used in the bombs to a buyer at a point of sale is not available to investigators.

“If you had a good taggant this would be a good thing for this kind of crime. It could help identify the point of manufacturer, and chain of custody,” Bob Morhard, an explosives consultant and chief executive officer of  Zukovich, Morhard & Wade, LLC., in Pennsylvania, who has traced explosives and detonators in use in the United States and Saudi Arabia, told MSNBC.com.  [...]

NRA officials seem more concerned about government use of technology to trace either firearms or the gunpowder used to make ammunition. [...] In the past, the NRA has argued that taggants could affect the trajectory of bullets and would also be a de facto form of weapons registration, reported the Los Angeles Times in 1995.

NRA lobbyists blocked the mandated use of taggants by gunpowder manufacturers. The NRA has therefore made it harder to track (mass) murderers.

The FBI said that gunpowder was an ingredient in the bombs planted along the Boston Marathon finish line. However, per The Hill:

Under current law, people can buy up to 50 pounds of explosive “black powder” with no background check, and can buy unlimited amounts of other explosive powders, such as “black powder substitute” and “smokeless powder.”

Senate Democrats are taking action:

Senate Majority Leader Harry Reid (D-Nev.) on Tuesday introduced a bill that would require background checks to be run on anyone buying explosive powder, a reaction to last week’s Boston Marathon bombing.

Reid introduced the bill on behalf of Sen. Frank Lautenberg (D-N.J.), who was out sick for some time. His bill would require a background check for the purchase of any of the powders. Plus, the attorney general could block sales of explosives if a background check shows the person applying for one is a known or suspected terrorist, and if there is reason to believe that the explosives would be used for terrorism.

A permit would also be required for making homemade explosives.

Greg Sargent has more, including this:

Aside from the substantive merits of the proposal, one of the political goals here is to challenge Republicans by testing just how far they are willing to go in opposing governmental action of this kind… to see if there is anything that Republicans are willing or ideologically able to support or if there is any common ground to be found anywhere.

Or do they just want innocent people to keep dying so they can eke a few more votes from their rabidly gun-supporting base, and pocket more cash from gun manufacturers and the NRA? Rhetorical.